title: Expression and distribution of GnRH, LH, and FSH and their receptors in gastrointestinal tract of man and rat.
abstract: BACKGROUND
  Gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) regulate the reproductive axis. Their analogs have been found to influence gastrointestinal activity and enteric neuronal survival. The aims of the study were to investigate expression and cellular distribution of GnRH, LH, and FSH and their receptors in human and rat gastrointestinal tract.
  
  
  METHODS
  Bioinformatic analysis of publicly available microarray gene expression data and Real-Time PCR mRNA quantification were used to study mRNA expression levels of hormones and receptors in human intestinal tissue. Full-thickness sections of human ileum and colon, and rat stomach, ileum, and colon, were used for immunocytochemistry. Antibodies against human neuronal protein HuC/D (HuC/D) were used as general neuronal marker. LH and FSH, and GnRH-, LH-, and FSH receptor immunoreactive (IR) neurons were evaluated.
  
  
  RESULTS
  GnRH1 mRNA was detected in both small and large intestine, whereas GnRH2 was mainly expressed in small intestine. Approximately 20% of both submucous and myenteric neurons displayed LH receptor immunoreactivity in human ileum and colon. In rat, 4%-9% of all enteric neurons in fundus and ileum, and 13% of submucous neurons and 21% of myenteric neurons in colon were LH receptor-IR. Neither mRNA (man) nor the fully expressed proteins (man and rat) of LH and FSH, or GnRH and FSH receptors, could be detected.
  
  
  CONCLUSIONS
  GnRH1 and GnRH2 mRNA are expressed in human intestine. LH receptor-IR enteric neurons are found along the entire gastrointestinal tract in both man and rat.
authors.affiliation: Department of Experimental Medical Science, Neurogastroenterology, Lund University, Sweden; Department of Clinical Sciences, Division of Internal Medicine, Skåne University Hospital, Malmö, Lund University, Lund, Sweden.
authors.forename: Elin
authors.initials: E
authors.lastname: Sand
authors.forename: Monika
authors.initials: M
authors.lastname: Bergvall
authors.forename: Eva
authors.initials: E
authors.lastname: Ekblad
authors.forename: Mauro
authors.initials: M
authors.lastname: D'Amato
authors.forename: Bodil
authors.initials: B
authors.lastname: Ohlsson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D005260:Female; D005640:Follicle Stimulating Hormone / Q000235:genetics / Q000378:metabolism*; D041981:Gastrointestinal Tract / Q000378:metabolism*; D015870:Gene Expression; D020869:Gene Expression Profiling; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007986:Luteinizing Hormone / Q000235:genetics / Q000378:metabolism*; D008297:Male; D009928:Organ Specificity; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D011962:Receptors, FSH / Q000235:genetics / Q000378:metabolism; D011974:Receptors, LH / Q000235:genetics / Q000378:metabolism; D011966:Receptors, LHRH / Q000235:genetics / Q000378:metabolism; D055815:Young Adult
chemical_list: D011962:Receptors, FSH; D011974:Receptors, LH; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C047717:LHRH, His(5)-Trp(7)-Tyr(8)-
keywords: Follicle-stimulating hormone (FSH); Gastrointestinal tract; Gonadotropin-releasing hormone (GnRH); Luteinizing hormone (LH); Man; Rat